Apparatus and Method of Single-In-Line Embedded Modem

1. A single-in-line modem constructed on a printed circuit board having a portion for analog circuits and a portion for digital circuits, the single-in-line modem comprising: an analog circuit configured to bi-directionally communicate with an external data communication equipment over a phone line using an analog protocol; a digital circuit isolated from the analog circuit and configured to bi-directionally communicate with a host system over a digital interface; an isolation region with a predetermined separation distance between the analog circuit and the digital circuit on the printed circuit board to protect from over-voltage hazards; a set of isolation capacitors over the isolation region to connect the digital circuit and the analog circuit; at most one pin header coupled with the printed circuit board and disposed along an edge of the printed circuit board; at most one single-in-line interface having at most one single row of pins selectively coupled to the analog circuit and the digital circuit, the single row of pins protruding from the pin header in a direction parallel to or coplanar with the printed circuit board for enabling the printed circuit board to be vertically coupled with a second printed circuit board, the single row of pins including at least an isolation spacer, a ground pin, and a power pin, the ground pin being disposed between the isolation spacer and the power pin and wherein the isolation region includes at least a first section, a second section, and a third section, the first section being connected to the third section through the second section, the first section being perpendicular to the second section, the second section being perpendicular to the third section.

2. The single-in-line modem of claim 1 , wherein the analog circuit includes: a diode bridge to rectify the inputs from the external data communication equipment; a set of discrete components to match the impedance and the power dissipation requirement of the external communication equipment; a direct access arrangement; and an interface to the isolation capacitors, from which to connect to the digital circuit.

3. The single-in-line modem of claim 1 , wherein the digital circuit includes: a digital signal processor configured to process digital data related to the communication protocol, an interface to the isolation capacitors, from which to connect to the analog circuit, and an interface to the host system on a main-board. The digital signal processor, the interface to isolation capacitor, and the interface to the host system are integrated in a single chip.

4. The single-in-line modem of claim 1 , wherein the digital circuit includes: a controller chip that contains an interface to the isolation capacitors, from which to connect to the analog circuit, and an interface to the host system to handle data transfers between the host and the modem.

5. The single-in-line modem of claim 1 further comprising a mounting hole disposed in the isolation region and disposed at a second edge opposite to the single-in-line interface, the mounting hole being configured to provide additional mechanical support.

6. The single-in-line modem of claim 1 , wherein: the single-in-line interface including at least a digital interface configured as a parallel interface that includes an 8-bit data bus, an address bus, interrupt, reset, chip select, write enable, and read enable signals.

7. The single-in-line modem of claim 1 , wherein: the single row of pins includes at least digital signals configurable to a serial interface to connect to a host system, selectable by user.

8. The single-in-line modem of claim 7 , wherein: the serial interface includes transmit data, receive data, request to send, clear to send, data carrier detect, ring indicator, reset, auxiliary signals for status monitoring, and unconnected reserved for future use pins.

9. The single-in-line modem of claim 1 , wherein: the pin header is a 20-pin single row connector header.

10. The single-in-line modem of claim 9 wherein pin positions of the pin header are on 0.1″ pitch.

11. The single-in-line modem of claim 9 wherein pin positions of the pin header are on 2 mm pitch.

12. The single-in-line modem of claim 9 wherein the pin header contains a pin assignment in an order of TIP and RING positions, empty space pin positions, a ground pin position, a power pin position, and then digital signal pin positions, wherein the TIP and RING positions are exchangeable, and wherein the digital pin positions are exchangeable.

13. The single-in-line modem of claim 1 further comprising at least a dual RJ11 connector coupled with at least a TIP pin and a RING pin of the single row of pins.

14. The single-in-line modem of claim 1 , wherein: a single-in-line pin connector is mounted to the printed circuit board so that the single-in-line modem is adapted to mount vertically with respect to a main-board.

15. The single-in-line modem of claim 1 , wherein: a single-in-line pin connector is mounted to the printed circuit board so that the single-in-line modem is adapted to mount horizontally with respect to a main-board.

16. The single-in-line modem of claim 1 , further comprising: a mounting hole to provide additional mechanical support when the single-in-line modem is mounted horizontally with respect to a main board.

17. The single-in-line modem of claim 1 , further comprising: a separate RJ11 connector for TIP and RING connection.

18. A single-in-line modem constructed on a printed circuit board having a portion for analog circuits and a portion for digital circuits, the single-in-line modem comprising: an analog circuit configured to bi-directionally communicate with an external data communication equipment over a phone line using an analog protocol; a digital circuit isolated from the analog circuit and configured to bi-directionally communicate with a host system over a digital interface; an isolation region with a predetermined separation distance between the analog circuit and the digital circuit on the printed circuit board to protect from over-voltage hazards; a set of isolation capacitors over the isolation region to connect the digital circuit and the analog circuit; at most one pin header coupled with the printed circuit board and disposed along an edge of the printed circuit board; at most one single-in-line interface having at most one single row of pins selectively coupled to the analog circuit and the digital circuit, the single row of pins protruding from the pin header in a direction parallel to or coplanar with the printed circuit board for enabling the printed circuit board to be vertically coupled with a second printed circuit board, the single row of pins including at least an isolation spacer, a ground pin, and a power pin, the ground pin being disposed between the isolation spacer and the power pin; and a mounting hole structure disposed in the isolation region and disposed at a second edge opposite to the single-in-line interface, the mounting hole being configured to provide additional mechanical support.

19. The single-in-line modem of claim 18 , wherein the analog circuit includes: a diode bridge to rectify the inputs from the external data communication equipment; a set of discrete components to match the impedance and the power dissipation requirement of the external communication equipment; a direct access arrangement; and an interface to the isolation capacitors, from which to connect to the digital circuit.

20. The single-in-line modem of claim 18 , wherein the digital circuit includes: a digital signal processor configured to process digital data related to the communication protocol, an interface to the isolation capacitors, from which to connect to the analog circuit, and an interface to the host system on a main-board. The digital signal processor, the interface to isolation capacitor, and the interface to the host system are integrated in a single chip.

21. The single-in-line modem of claim 18 , wherein the digital circuit includes: a controller chip that contains an interface to the isolation capacitors, from which to connect to the analog circuit, and an interface to the host system to handle data transfers between the host and the modem.

22. The single-in-line modem of claim 18 , wherein: the isolation region includes at least a first section, a second section, and a third section, the first section being connected to the third section through the second section, the first section being perpendicular to the second section, the second section being perpendicular to the third section.

23. The single-in-line modem of claim 18 , further comprising: a separate RJ11 connector for TIP and RING connection.

24. The single-in-line modem of claim 18 , wherein: the single-in-line interface including at least a digital interface configured as a parallel interface that includes an 8-bit data bus, an address bus, interrupt, reset, chip select, write enable, and read enable signals.

25. The single-in-line modem of claim 18 , wherein: the single row of pins includes at least digital signals configurable to a serial interface to connect to a host system, selectable by user.

26. The single-in-line modem of claim 25 , wherein: the serial interface includes transmit data, receive data, request to send, clear to send, data carrier detect, ring indicator, reset, auxiliary signals for status monitoring, and unconnected reserved for future use pins.

27. The single-in-line modem of claim 18 , wherein: the pin header is a 20-pin single row connector header.

28. The single-in-line modem of claim 27 wherein pin positions of the pin header are on 0.1″ pitch.

29. The single-in-line modem of claim 27 wherein pin positions of the pin header are on 2 mm pitch.

30. The single-in-line modem of claim 27 wherein the pin header contains a pin assignment in an order of TIP and RING positions, empty space pin positions, a ground pin position, a power pin position, and then digital signal pin positions, wherein the TIP and RING positions are exchangeable, and wherein the digital pin positions are exchangeable.

31. The single-in-line modem of claim 18 further comprising at least a dual RJ11 connector coupled with at least a TIP pin and a RING pin of the single row of pins.

32. The single-in-line modem of claim 18 , wherein: a single-in-line pin connector is mounted to the printed circuit-board so that the single-in-line modem is adapted to mount vertically with respect to a main-board.

33. The single-in-line modem of claim 18 , wherein: a single-in-line pin connector is mounted to the printed circuit board so that the single-in-line modem is adapted to mount horizontally with respect to a main-board.

34. The single-in-line modem of claim 18 , wherein the mounting hole provides the additional mechanical support when the single-in-line modem is mounted horizontally with respect to a main board.